Process of making 1-methyl-5-chlorobenzene-2-carboxamino-3-thioglycollic acid



Patented Feb.

T-ON-THE-MAIN, LER, or HOCHST-ON-THE-MAIN, GERMANY, Assionons T0 ERWIN HOFFA, OF HOCHS MAIN, AND FRITZ MUL GRASSELLI DYESTUFF CORPORATION, DELAWARE.

PROCESS OF MAKING 1-METHYL 5-CH No Drawing.

Application \Ve have found, that 1-1ncthyl-5- cyanobenzene-ZB-tliioglycoll mula:

however prepare manner with aci d, when d saponif verted into a new compound which mg to our 1nvest1gat1ons, .has the constitution of a carboxyaminoacid of the formula:

6 -coNm 4 somcoon filfid. August 9, 1927,

ANDJENS MOLLER, OI HANAU-ON-THE- OF NEW YORK, N. Y., A CORPORATION 01' LOROBENZENE-2-CARBOXAMINO-3-THIOGI|Y- COLLIC ACID.

chloro-Q- ic acid of the fortreatcd in a suitable ymg agents is conaccordchemical thioglycollic The reaction probably is effected according to the following equat1on:

CONHi s-om-coon o1 S-CHz- COOH This is surprising fact, as Friedlander (see Liebigs Annalen, v0 that the cyanobenzene-o the formula:

SCHzOOOH.

is stable to the action of acids, and

unattacked even trated hydrochloric aci runs quite smoo compound in a very state. The new white crystalline ganic solvents, soluble when boiled with (1. Our new process the new ood yield, and in a pure is, when dry, a

thly and produces a compound 1. 351, page 415) states -thioglycollic acid of remains concenpowder, easily soluble in orlizing from dilute alcohol in almost at 173474;". 13y the action needles, melting subject matter 0 f our copending up in hot Water,

crystalcolorless elevated temperature the G-chloroi-methyl- -2-carboxylic aci -3-hydroxythioh process is the plication Serial No. 211,850, and in Germany April 16, 1927.

No. 211,852 filed Aug. 9, 1927. It may be used, therefore, as a new parent material for the production of 6.6?dichlo1 oA/P-dimethylthioindigo.

The following examples will further illus-. trate our invention, the parts being by weight and all temperatures in centigrade degrees; it is understood that our invention is not limited to the particular proportions, reaction conditions or materials listed therein.

1. 10 parts of 1-methyl-5-chloro-2-cyanobenzene-3-thioglycollic acid, obtainable for instance accordin to the process described in British Patent 1%. 18,292/1914, are introduced into about 180 partsof hot sulfuric acid of 90% strength and the solution is kept for about an hour at the temperature of about 90". After cooling down, the reaction mixture is poured into vater and the mixture is allowed to stand for some hours. The separated product of reaction is almost entirely pure, melting at 171-472". It may be recrystallized from dilute alcohol, yielding then almost colorless needles melting at 17 34749. It is easily soluble in organic solvents, soluble in hot water. The yield obtained is almost theoretical. I

2. 10 parts of 1-methyl-5-chloro-2-cyanobenzene-l-thioglycollic acid are dissolved in about 200 parts of concentrated sulfuric acid of 66 B. and the solution is allowed to stand at room temperature for some days. Then it is poured into water and the isolation of the separated product of reaction is carried out as described above. It is identical with the product of Example 1.

In some casesit is advantageous to add boric acid to the sulfuric acid solution.

We claim:

1. Process 1 methyl-5-chloro-2-cyanobenzene-3-thioglycollie acid ofthe formula 01 SCHzCOOH d to treatment with sulfuric acid until the corresponding .Q-carboxyamino compound is formed, and stopping the reaction before further conversion of the said 2-carboxy amino compound by dilution of the reaction mixture.

2. Process for the manufacture of 1- methyl 5-chloro-benzene-2-carboxyamino 3- thioglycollic acid'of the formula A C-NH:

4 cm coon which comprises subjecting one part by ERWIN HOFFA. JENS MULLER. FRITZ MULLER. 

